In February and March 2007, we passed a survey on 1437 students from different schools in Liège, Belgium. This research is a replication of a research done in the same schools – but one – in 1990 by one ... [more ▼]

In February and March 2007, we passed a survey on 1437 students from different schools in Liège, Belgium. This research is a replication of a research done in the same schools – but one – in 1990 by one of us. However, several questions were added to the 2007 questionnaire in order to apprehend the new dimensions that we developed over the last 17 years. The results which are presented here are only preliminary; further analyses are being undertaken. More sophisticated statistical methods are used to explore the two databases. [less ▲]

The collision of Deep Impact with comet 9P/Tempel 1 generated a bright cloud of dust which dissipated during several days after the impact. The brightness variations of this cloud and the changes of its ... [more ▼]

The collision of Deep Impact with comet 9P/Tempel 1 generated a bright cloud of dust which dissipated during several days after the impact. The brightness variations of this cloud and the changes of its position and shape are governed by the physical properties of the dust grains. We use a Monte Carlo model to describe the evolution of the post-impact dust plume. The results of our dynamical simulations are compared to the data obtained with FORS2, the FOcal Reducer and low dispersion Spectrograph for the VLT of the European Southern Observatory (ESO), to derive the particle size distribution and the total amount of material contained in the dust ejecta cloud. [less ▲]

The study is conducted in the frame of a programme of monitoring of all landfill sites in Wallonia. The "odour" part is assigned to ULg. The present report concerns more particularly a campaign on the ... [more ▼]

The study is conducted in the frame of a programme of monitoring of all landfill sites in Wallonia. The "odour" part is assigned to ULg. The present report concerns more particularly a campaign on the site of Malvoisin. Besides the usual field inspection technique, the research group has used GC-MS to estimate the chemical composition of the atmosphere over the tipping area, dynamic olfactometry and flux emission chamber to assess the odour flux generated by the waste material and a survey in the surrounding population. [less ▲]

The present deliverable aims at providing any CoP member, CoP animator or CoP mediator with the most complete view of the PALETTE tools and services. It gives a voice to the developer, the educationalist ... [more ▼]

The present deliverable aims at providing any CoP member, CoP animator or CoP mediator with the most complete view of the PALETTE tools and services. It gives a voice to the developer, the educationalist, the ergonomist and of course the user to explain how they consider them. So, it suggests use cases, scenarios but also shows to the reader where are the obstacles of use (with the aim of avoiding a too quick discouragement on his/her part) and it provides real users’ testimonies. It illustrates the participative design, core of the project, by showing how various kinds of partners in the project work at their evolvement. Several times, it evokes how they interact in that way. More, for the sake of completeness, external services which are "social network" oriented, are described in terms of functionalities and with the concern of providing the audience with a largest view of how ICT may help CoPs to grow up. [less ▲]

The CIGRE WG C4.601 on Power System Security Assessment was formed in August 2004, at the CIGRE Session 2004 and was given the charter to specifically look at the following needs in the industry: 1. The ... [more ▼]

The CIGRE WG C4.601 on Power System Security Assessment was formed in August 2004, at the CIGRE Session 2004 and was given the charter to specifically look at the following needs in the industry: 1. The design of controls to enhance system security. This includes local device controls as well as system wide area controls and remedial action schemes. 2. Modeling of existing and new equipment required for power system analysis. (In this task it was felt that the most pertinent and timely activity was to look at the modeling and dynamic performance of wind generation systems.) 3. The design of monitoring systems for real time stability evaluation and control. 4. New analytical techniques for assessment of power system security. In addition to advances in computational methods, this includes the development of emerging approaches such as risk-based security assessment and the application of intelligent technologies. To this end, all of the above subject matters were tackled by the Working Group. More specifically, of the more than one hundred members and contributors to the work, three adhoc groups were developed within the Working Group, each given the task to address one of the first three subject matters above. The fourth task is one that the working group as a whole has presently started on, after having finished the other three tasks. The three completed tasks have resulted in the publication of three CIGRE Technical Brochures. These are: • CIGRE Technical Brochure on Wide Area Monitoring and Control For Transmission Capability Enhancement (this effort was lead by C. Rehtanz) • CIGRE Technical Brochure on Modeling and Dynamic Behavior of Wind Generation as it Relates to Power System Control and Dynamic Performance (this effort was lead by P. Pourbeik) • CIGRE Technical Brochure on Review of On-Line Dynamic Security Assessment Tools and Techniques (this effort was lead by K. Morison) During the course of the work, in addition to the formally elected WG members a large number of others contributed significantly to these efforts. All have been properly acknowledged. The combined group of members and contributors constituted 125 experts from 25 countries. These included experts from equipment manufacturers, utility engineers, consultants and research organizations around the world. The work on the three Technical Brochures mentioned above was completed in December 2006, with final reviews and approvals before publication occurring in early 2007. Thus, the work took nearly two and a half years to complete. All three documents constitute timely and valuable information for transmission system planer, operators, reliability organization and engineers in research and consulting firms. As stated previously, the Working Group is currently working on its last assignments (item 4. above). It is expected that this will be reported on in the near future. [less ▲]

At the microscale, classical bearings such as ball bearings, sliding bearings and other pivots may be difficult to manufacture. Among all possible solutions to replace them, the notch hinge seems to be ... [more ▼]

At the microscale, classical bearings such as ball bearings, sliding bearings and other pivots may be difficult to manufacture. Among all possible solutions to replace them, the notch hinge seems to be very attractive through its many advantages. The major limitation is on the rotation angle. This paper presents a new simplified analytical model for the prediction of the maximum angular displacement and the angular stiffness of a notch hinge. To validate our model, an experimental set-up has been developed. Finally, the results are compared to other theories. [less ▲]

This paper proposes the use of the stochastic frontier approach to analyse the relationship between cognitive performance, retirement and non-professional activities of the 50+ individuals using data from ... [more ▼]

This paper proposes the use of the stochastic frontier approach to analyse the relationship between cognitive performance, retirement and non-professional activities of the 50+ individuals using data from three surveys conducted in Europe (the Survey on Health, Ageing and Retirement in Europe and the English Longitudinal Survey on Ageing) and United States (the Health and Retirement Study). Next to the strong relationship between cognitive performance, age and education, this study highlights the negative effect of retirement and the positive impact of non-professional activities and social contacts. [less ▲]

Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are far more abundant along our coast compared to the beginning of the nineties. Human impact on these species is however hard to ... [more ▼]

Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are far more abundant along our coast compared to the beginning of the nineties. Human impact on these species is however hard to establish, mainly due to lack of information on marine mammal population ecology, density, distribution and diversity. This project aims to gain further knowledge on the viability of the harbour porpoise and harbour seal populations in the North Sea (focusing mainly on its southern Bight) through - The characterisation of their genetic structure and diversity (through mtDNA and microsatellites in harbour porpoises) - A better understanding of their feeding ecology (through δ13C and δ15N measurements in muscles) - The assessment of their susceptibility of being trapped accidentally in fishing nets (post-mortem investigations) Harbour porpoise and harbour seal occupied the top trophic levels but displayed different feeding habits as inferred from their δ13C and δ15N mean values. Harbour porpoises displayed lower mean δ15N values suggesting a lower trophic position likely oriented towards small planktivorous fish such as herring and lesser sandeel. However, both their recent high abundance and their dietary preferences might lead to a higher susceptibility to by-catch as revealed by the significant emergence of net entrapment and net marks revealed by post-mortem investigations. The question rises about the sustainability of these incidental captures. Furthermore, genetic investigations revealed a higher fragmentation of the porpoises collected along the coast of France, Belgium and Netherlands. This apparent fragmentation is of particular importance from a conservation point of view and enhances the fact to protect in priority these last populations. Our study showed importance of multidisciplinary approaches (post-mortem investigations, stable isotope measurements (δ13C and δ15N measurements) and genetic investigations using mtDNA and microsatellites) to apprehend the question of marine mammal survival in our waters. [less ▲]